Resilient vehicle wheel



A. H. TRACY RESILIENT VEHICLE WHEEL Jan. 29, 1946.

Filed Nov. 2:5, 1942 2 sheetssheet 1 Jan. 29, 1946.

A. H. TRACY RESILIENT VEHICLE WHEEL Filed Nov. 25.- 1942 2 sheets-sheet 2 Patented Jan. 29, '1946 UNITED STATES PATENT OFFICE .12,393,721 RESILIENT VEHICLE WHEEL l Atlee H. Tracy, Sarasota, Fla. ApplicationNovember. 23, 1942, serial No. 456,545

(ci. s-r) 20 Claims.

This invention relates to resilient vehicle Wheel structures and is adapted for use in connection with Wheels used on automobiles, trucks, airplane landing gear and the like, and the invention is also suitable for heavybombing planes and gun carriages.

It is an object of the invention to provide. a resilient wheel provided with a puncture-proof tread and having one ormore inflated tubesso arranged within a wheel casing as to be adequately protected against puncture-'dirt and water, and at the same time, providing substantially unrestricted'cush'ioning action to absorb road shocks.

The improved wheel includes an outer puncture-proof rim having a suitable tread surface and forming a part of a drum-like'enclosure for the pneumatic tube or tubes enclosed therein.

In the present invention, the pneumatic tubes are secured to an inner rim, which, in turn, is rigidly mounted on the wheel disc and fixed to the hub of the wheel and may be attached to any suitable part, such as the usual brake drum. 'Ihe inner wheel including the pneumatic tube or tubes isv free to roll Within the outer rim to which the tread surface may be secured. By this construction, the angular speed of thevinner wheel and pneumatic tube thereon may be somewhat greater than the angular speed of the rigid tread. i'

Other objects and advantages will be herein-A after-more fully described, and for a complete understanding of the nature, scope and characteristics of the invention, reference may now be had to the following description and accompanying drawingsin which latter:

Fig. 1 is a view of the lower half of a, vertical section of one embodiment of the invention including a single pneumatic tube and is adapted for use on automobiles or other comparatively light vehicles, including smaller` types of trucks andairplanes. l Fig. 2 is a sectional view'sim'ilar to Fig. 1, but illustrates a construction including two pneumatic tubes in -side-by-side position forl heavier duty applications. v l

Fig. 3 is a similar sectional view of anotherem bodiment and illustrates the use of a plurality of coplanar pneumaticv tubes one within the inner periphery of the other' for use Where greater vertical flexibility is desired than in the usual situa- Fig. 4 is a sectional view similar toFig. 3, but illustrates the' use of twol sets ofsuch coplana-r pneumatic vtubes in side-,by-side relationship' for use where 'both heavy duty and-vertical flexibility are desired. I

; ends of the tire casing-holding ring.

Referring to these drawings in detail, the embodiment shown in Fig. 1 comprises a wheel hubstructure which may include the usual brake drum and housing I, to which latter may be secured in the usual manner, as by bolts, a wheel disc 2 having an inturned annular flange 3. In fact, the same or similar circular series of bolts as are now used to secure the wheel to the hub structure, indicated by bolt 2a, may be used for this wheel disc 2. A cylindrical rim 4 is secured to the flange 3, as by rivets as illustrated, or it may be welded, or otherwise secured. A flexible tire cover 5 is secured by rings 6 to the rim 4. The rings 6 are snugly supported on the rim 4.

While for certain phases of the invention, the ordinary tire casing rim and attaching means may be used, I prefer that this inner tube casing 5-consist ofone or more layers, of heavy canvas which is not impregnated with rubber, 'but which should be treated to prevent rot from moisture. Since the space in which the inner tube and its surrounding `casing operates is entirely closed, as 'will hereinafter appear, against dirt and water, there is very little chance for rapid deterioration of the casing but changes of temperature can cause slight amounts of moisture, and mainly for this, reason, it would be desirable to waterproof the casing. A single heavy layer of heavy cotton duck would be amply strong to withstand the air pressure now used in inner tubes, but it would be desirable to use more than one layer as an added factor of safety. However, a large number of layers might be detrimental as tending to prevent radiation of heat and would be unnecessary from a mechanical strength standpoint.

To hold the inner tube casing 5 on the rim, the edges are turned back and sewed to the body of the casing to form a pocket along each edge. The ring 6, which may be solid or in the form of a stranded cable, is cut at one point as shown in Fig; 6, andthe threaded ends-provided ,with a suitable coupling to secure said ends together. With this arrangement, the rings 6 mayV be threaded into the pockets through a slit in the hem or pocket at any desired point, Iand when the two ends are brought together, they may be fastened by the coupling. This coupling may be that shown in Fig. 6 wherein the bottoms of the cup' or sleeve members 6a are rotatably secured together, so that by bringing the two ends of rod casingfor the pneumatic .tube or tubes.

place, the edges of the tube casing will be rm- Yly secured to .the'rim 4. f

A pneumatic tube 1 is mounted in theAcover 5 and may be inflated to any desired pressure inl the usual manner. The tube 1 may be similar to` the usual automobile tire inner tube. YItis slightly smaller for the same size wheel and vmay have even thinner walls since it is practically puncture-proof. f

The structure just described is enclosed in av drum-like casing including a tread ring assembly portion '8 to which are secured sheet -metal side Y [covers or members in the form of i an annular plate 9 having a central opening for access to the Wheel securing bolts 2a and a removable cap 9b, like aV hub cap, to close said opening normally. Said plate I-ispsecured .to the-outer edge of the ring assembly 8. VAri annular plate lois-secured near its outer periphery to the inner edge of theV ring assembly V8. y Y

The tread ring assembly 8 comprises a pair of concentric cylindricalsteel rings II and I2, which rings are secured together' bymeans of spacers I3 in the form of flanged sheet metal rings ex- V tending around'thert'read assembly` ring 8, and

preferably welded at the flanged edges to the rings II and I2. Tubular connectorsY I4 internally threaded at the ends are passedthrough the spacers: I3, and the cover or side plates 9 and I0 it is preferred that it comprise a ball 35 projecting from the end of a retaining tube 3b with a suitable Washer and coiled spring in the tube bearing against the ball, the 4tube being screwed into a bracket 31 secured as by bolting or otherwise tothe edge of the rim 4. A disc or washer screwed into'the tube 3b confines and backs up the coiled spring, and a washer stem prevents excessive'movement of the ball.

In this way, the drum-like enclosure of the exible tire or tires is kept in' proper position on said tire or tires and on the rim and wheel structure as awhole. The .tread ring assembly should not depart by any detrimental amount from its normal position, in which normal position that part of the outer contact surface of the ring assembly,l which is in contact with the road surface, is substantially parallel to the axle of the wheel. In addition the flange I1 and plate I 6, with the grease channel therebetween, form a moisture and dirt-proof connection, so that moisture and dirt entering the drum-like casing through thevopen center of plate IIlgcannot get into the are rigidlyclamped to the tread assembly byv means of machine screws I5 threaded into'the ends ofY the connectors I4. The cover or sidev plates-9 and I0 are depressed at 9a and I 0a, re-V spectively, so thatthe ends of the screws I5 `may be flush with the outer surface of the'wheel.

There are six, eight, or more of these Vtubular connectors I4 spaced equally in the tread ring. They Vare Yhollow and r'may be used to receive exact balancing weights for the wheel, if so desired. Y

' VThe tread assembly and side members 9 and I0 thus described, form a drum-like enclosure or This rnust, of course, be kept-in proper `position on the rim and tube or tubes. For this purpose, an annular plate IB is secured, as by welding, to the inner surface of the side plate III and the adjacentv edge of the tire rim 4 is provided with an outwardly extending flange I1 which is in Vsliding contact with the plate I6.v This ange I1 is an annular stamping separate from the rim 4 `for ease and cheapness of manufacture' and conven- `flexible tirechamber or channel, and said tires are protectedY therefrom. The plate 9 and its Yhub cap 9bfentirely vclose this side of the drumlike tread casing of the wheel, so that dirt and moisture cannot get into thevwheel from its outer side; The ball castors provide suiiicientbearing between the rim and plate 9 on this side, and

the flexible tire casings are still rprotected from' moisture and dirt.

l The flange IT performs an additional function in tending to prevent crushing of the inner tube and its Icasing and the Ventire collapse of the tread casing and wheel in case of the deflation of the tire orfin experiencing heavy bumps. ForVV this, the edge I11'l of .the sliding flange I1 extends outwardly to such an extent that when for any reaj son the tread ring approaches the flexible tire rim suiiiOiently, Vsaid edge I1a will engage the ring I2 of the tread and prevent the further approach. Thus, -the flexible tire and tube |are protected fromcrushing and the wheel from collapsing.-

VThe plate I6 attached to the inside of plate IU is provided with an angular or chamfered inner edge I8 and thecover platel yis provided with drainage holes I9 closely adjacent this chamfered surface, so as to drain any moisture from within the central part of the casing. y

cylindrical tread ring member I2 may also y beY provided with annular ribs 2| and drainage ience in assembling or disassembling for any i purpose and is bolted in position on the rim, as n shown. A

. The flange I1 is formed 2U, which provides a grease pocket for lubricating the contacting surfaces of the plate I5 and flange I1. This grease'pocket preferably con- Atains'a felt or other filling which is saturated with the grease.

In order thatthis flange I1 may be kept pressed Y up against the side plate I0 with a resilient pressure; the opposite edge of the rim is provided at intervals, preferably60 apart, Ywith outwardly spring-pressed balls 35, Yas in ball castors, presswith an annular rib holes 22 between these ribs and the adjacent cas-.I ing wall. These will prevent grease which may escapefrom the pocket 20, or otherwise, from reaching the tread surface of the tire cover 5 and'Y the cooperating inside surface of the tread ring I2. This excess grease is thrown out by centrifugal V:force through the holes 22 into the space lbetween the inner and outer tread rings l I and I2. There are, of course, as many of these holes 22 ras desired. The grease can be cleaned out of the tread ring by taking olf one or both of the plates 9 and I0, as occasion requires.

The material Vconstituting the tread on the tread ring-is as follows: an inner layer 23, consistingr ofi three or four layers of heavy cotton c1eth,is overlaid by a layer of rubber belting 24. This, in turn, is overlaid by several strips of solid rubber 25 which form the actual road contact surface. Rivets 26 through each `rubber strip at several points around the ring and through the belting and cotton layers, with their washers, bind these layers together and into a circular member which can be slipped over the outer surface of the solid tread ring I I and secured in position thereon. As indicated, the layer of cotton cloth 23 is slightly wider than the metallic tread ring I I and is folded inwardly thereover as shown, and is securely fastened all the way around the tread ring between the end plates 9 and I0 and the edges of the tread ring II when the bolts I are tightened and held by suitable lock washers. The side plates 9 and I0 of the tread ring casing are of sulcient diameter, as shown, to overlap the edges of the belting 24.

The side plate 9 is provided with a central opening' of a size permitting ready access to the bolts 2a used to secure the rim plate 2 to the hub or brake drum structure, and a removable cap 9b corresponding to the usual hub cap is secured to plate 9 in any desired way over this opening.

For ready access to the valve stem of the inner tube for inflation purposes, the end of the valve stem, as is usual in trucks, kmay have a small pipe or tube leading therefrom to another or auxiliary stem, with or without its own valve as desired, located on the plate 2 at a point which is readily accessible when the hub cap 9b is removed. These valve stems are not shown, for the sake of simplicity and clearness in the drawings, but are well known and their location and manner of installation and connection for inflation purposes are well understood.

'I'he manner of assembling and use of the invention are thought to be evident. The completed wheel, with the hub cap 9b off, is slipped on over the brake drum housing of the vehicle, as is customary in mounting wheels, and thebolts or nuts 2a are tightened to secure the wheel in position. The hub cap is then placed in position on the plate 9. If necessary to reinflate the tire, the same may be done through the auxiliary stem by removing the hub cap. If for any reason, it is necessary to get at the stem on the tube or to change the pneumatic tires, the same may be done by removing the wheel casingentirely and also the side plate 9, or both plates 9 and I0 and the flange I1.

The tread ring I2 of the assembly 8 is preferably of an inside diameter substantially the same as the maximum diameter of the flexible tire casing 5, when the tire or vehicle is unloaded, or a little larger. Then, when the tire is compressed, as by a load on the vehicle, the hub is lowered and the flexible tire does not touch the inside of the upper part of the tread ring. This is intended to be shown diagrammatically in Fig. 5 wherein the space 3l at the top between the top of the tire and the inside o'f the ring I2 is seen to exist. ThisI results in a movement which must be taken into account.

The outer tread assembly is rigid and therefore has a fixed diameter and thus a fixed radius but the radial distance from the center of the axle to the outer circumference of the inner tube casing is continually changing due to the flexibility of the inner tube. With insufficient air pressure and a heavy load, the wheel would revolve off center," i. e., the axle would not be at the center of the wheel. 'Ihe present type of wheel operates in exactly the same way (but by an amount which is hardly noticeable) because the tire is slightly flat where it rests on the road. For this reason,

the'inner tube and all other parts mechanically connected to the .axle make a slightlyk larger number of revolutions than thev rigid outer tread as sembly. In other words, the entire structure might be termed a wheel within a Wheel. The difference in the number-'of revolutions between the two parts of the `wheel is relatively small and depends to some extent on the roughness of the road. On the ordinary concrete highway, the average difference is on the order of about two per cent, i. e., the axle would make 102 revolutions for every revolutions of the rigid outer tread. This is the reason for the use of the sliding plates in the dust ring arrangement and the ball castor 35 on the other edge ofthe rim. They move relatively very slowly as compared to the wheel itself.

In case it should be said that the flexible tube casing 5 might slide or skid and wear on the inner surface of the tread ring I2, it may be pointed out that the very large area of contact (which is clean and dry), as compared to the contact area of the wheel on the road surface, makes that practically impossible. However, it would be cheap and easy to line the inside surface of the ring I2 with a material having a high coefficient ofV surface frictional resistance, if thought desirable, The flexible tire casing 5, it should be re'- membered, .does not slide on they inner surface' of tread ring I2, but rolls very slowly, as above described.

Fig. `2 illustrates an embodiment which is similar to that just described, with the exception that two pneumatic tubes are used in side-by-side relationship` This is intended mainly for use on trucks with heavy loads. In this construction, the rim 21 is wide enough to accommodate the two tube casings 5. v

The rim 21 is secured to the hub or brake drum I by a disc or annular plate 28 attached centrally to the drum by the usual bolts 2a, as in Fig. 1. At its periphery, it is connected to the inside of the rim 21 in any desired way, that shown involving radially slitting the edge at suitable intervals and bending the adjacent tongues or portions between slits alternately to one side and to the other to form lateral flanges 28a, which, in turn, are secured to the rim by bolting, riveting or welding. i

An annular inwardly extending ring 29 secured in any desired way to the inside of the tread ring I2, extends between Ithe pneumatic tube casings and engages the rim 2'I when the tires are deflated. This assists the side flange I'I in providing safety stops to prevent a complete collapse of the wheel or crushing of the tires when the tubes are deflated or heavy bumps are encountered. The tread construction in this embodiment is similar to that shown in Fig. 1, though wider to cover the two tires, and the other features are the same or substantially so, and are not here specifically described. Their construction and operation will be understood.

Fig.l3 is substantially similar' to the construction shown in Fig. 1 with the exception that two pneumatic tubes and casings one within the inner periphery of the other are mounted in the same plane. This arrangement is useful particularly on the leading or trailing wheels of the tricycle landing gear of airplanes. Here great Vertical flexibility is desired. In thisconstruction, a, floating annular rim or ring 30 is positioned between the pneumatic tubes and is arranged for sliding engagement at each edge with `the s ide plates 9 and I0 of the drum casting. -T'his sliding engagement device 'at the plate I0 or I6, "for instance.

comprises Va ring 3| having-at suitable intervals inwardly extending tongues 32, the' ends of which are split to permit bending one split endlaterally and inwardly-of thecasing, so that the two ends 33 and. 34 form a seat for the edge ofthe fioating rim or ring 30.Y This ring is not attached to anything, so that'it is free .to slide in all directions with respect to plate I or I6..V

At the plate 9, the construction and arrangement is slightly diiferent inrthaij two sliding rings .3|a and 3|b1areV provided zConnecting strips .between these rings areslit near the edge of rim or ring 30 and 'their ends bent laterally on both 3| bV against rim4 on the'plateY 9 side.`

Y Likewise the floating rim or ring 30 will be prevented from crushing down on the tread rim Y|2 bythe outer edges'of sliding rings 3| and 3|a striking the inside of the'V tread ring I2. Y

Variations` in the air pressurebetween the two y tubes or sets of .tubes may be used to change the time element for the maximum vertical'movement ofthe rim, and, of course,.different sizes and shapes vof tires may be used. Y

`Fig 4 illustrates an'embo'diment'which is also similar to that 'shown in Fig; 3,*With the exception' that two sets of'pneumatic tubesareV used inside- .by-side relationship, and the proportions vof the associated elements are increased to conform with the'requirements of this embodiment. VThis form-is 'adapted fora landing 'wheel on big airplanes, 'such as the flying fortresses. Such planesweigh, roughly, fifty thousand pounds and land at a Vspeed of better than eighty miles per hour, which -is about one Vhundred and twenty feet per second.

As suggested, these Wheels are considered particularly useful in airplane landing gears. ySuch wheels are in actual use, that is, loaded, only a part ofgthe time. The remainder of the time, when the plane is in the'air, they are not in actual use-not loadedand it is desirable that they may be as lcompact and evenly balanced as possible'and without looseparts or complication at suchrtimes. VThe substantial filling of the radial space between the hub tire rims and the treads by the pneumatic tire lmeans, whether single or multiple tires and with or without floatingrims, when the wheels are not loaded, causes the off-center -parts to assume automatically their concentric positions by reason of the air pressure in the tires tending to restore them to normal unloaded 'form or cross-section. vThen when they are used, the weight or load transferred through the vaxle tothe wheels causes a. downward movement of the 'actual operating centers of the inside portions of the wheels, the vrotation thereof at vdifferent angular velocities from the tread ring, and the rolling of the ring and center in Figr, vwhere the flattening of -the;loaded tire Yis of advantage also where power may be applied to the centers to drive thef wheels. The greater lowering of the centers of the wheels with greater loads is-also an advantage in such power applications in giving greater leverage for the application of the power when the load increases.

Still another advantage in the centeringof the pneumatic tire parts in a tire of this rolling-contact type in airplane Yuse is the prevention thereby' Vof slippage of the pneumatic tires on the treads or other parts engaged in the inside of the wheel when the airplane lands. If the tread were hanging down below the tire parts just before landing, the tread would be turned rapidly before being pressed into engagement with the pneumatic tire parts. This would tend to cause slippage 'between the outer and inner portions of the wheel and perhaps damage to the tire before the inner parts could be brought up to speed. But with all the parts being centralized together and the coefficient of friction of rest being so much greater than that of movement, thewhole wheel would start to rotate together upon rst touching the surface in landing and there Ywould'be no internalslippage.

The centering of the parts when theV wheels are not in use `has its advantages even though the wheels are not used eventually for airplanes. 1n ordinary handling, storage, etc., yit is better and more satisfactory to have the parts of the ywheel f are more conveniently handled and better'carried if the' parts are centralized'and there .are no loose parts to shake'around.y I

From the foregoing, it is apparent that since the Wheel is made .almost entirely of pressed or stamped parts, itis even cheaper than'the present type including its tire. But what is far more important at this time, is that its use requires vastly less rubber.' Ther inner tube is the samelas at present, although it is slightly smaller for the same size of wheel and' may possibly even have thinner walls since it is practically punctureproof. The actual tread is preferably of solid rubber and will, of course, wear, but it can. be made of a much inferior gradey of rubberand Y there is less of it than there is in the present cas- Y cent.

transportation Yobtained for each pound of rubber it would seem that elimination of a spare wheel Y would bepossible and this would `lat once cut requirementsfor new equipment by twenty per- It is estimated that the ton mileage of actually worn away in surface contact by the road surface would be at least ve times las great 'as with the "presenttype of pneumatic tire.

--It is intended, of course,' that the invention shouldnot be limited to the specic embodiments disclosed herein, since modifications may be made, and it -is contemplated, therefore, by the 'appendedclaims to cover any such modifications as the true spirit and scope of this inven-` vfall within tion.

Having thus described the invention, what is claimed and desired to be securedzby Letters Patent is:

1. A resilient vehicle wheel comprising, in

combination, a tread ring, a tire rim therein conradially compressible in the llower part of the wheel and not. illing the entirefspace in the upper 4part when the Wheel is loaded, the rim fand ring being constructed and connected to rotate at diierent angular velocities when the wheel is rolling.

2. A resilient vehicle wheel comprising a ring with a substantially'ilat inside surface, a rim therein, a pneumatic tire secured circumferentially throughout to the rim and of a size substantially to reach the inside of the ring when the wheel is unloaded but to dropbelow the upper part thereof whenloaded, the ring and tire being constructed and proportioned to have diiierent angular velocities when the wheel is so loaded and moving and the tire to roll on the inside of the ring.

3. A resilient vehicle wheel comprising a `rela tivelyV rigid tread ring casing with a substantially fiat transverse inside tread surface, a rim therein connected with the hub structure of the wheel, a .pneumatic tire secured at its circumference throughout to the rim and ofia size substantially to reach the inside of the tread 'ring when the wheel is unloaded but to drop below the upper part thereof when loaded, the tread ring and tire and the rim being constructedand connected to have diierent angular velocities when. the' wheel is so loaded and moving and the tire toroll on the inside of the ring.

4. A resilient wheel structure comprising a tire rim, pneumatic tire means circumferentialiy secured thereto on the rim, a metallic tread ring having a substantially flat transverse inside surface surrounding the tire means and having side members overlapping the rim, the rim and ring being concentric when the wheel is unloaded but eccentric when loaded, the rim and ring being so constructed and connected that when the wheel is so loaded they operate at different angular velocities and the tire rolls on the inside of the ring, the rim having sliding engagement with the inside surface of the adjacent side member, and a dirtand moisture-proof connection therebetween.

5. A resilient Wheel structure comprising a tire rim, pneumatic tire means on the rim, a metallic tread ring or casing surrounding the tire means and having side members overlapping the rim,

the rim and being concentric when the wheel is` unloaded but eccentric when loaded, the rim and ring when the wheel is so loaded operating at different angular velocities, the rim having movable engagement with the side members, and safety stop members to prevent the rim approaching so closely to the tread member or assembly as to cause damage to the pneumatic tire parts.

6. A resilient wheel comprising a hub structure, a rim carried thereby, pneumatic tire means on the rim, and a rigid tread casing enclosing the tire means and rim and concentric therewith when the wheel is not loaded but eccentric thereto when loaded, said casing having a tread ring assembly and .side members extending inwardly and past `the saiclrim, theV ring and .operating at different angular velocities whenthe :wheel is f loaded and rolling, Vthe rim having' a. sliding .en-

gagement with the inner face of theinside member ofthe said casinganclaresilient engagement with theinside ofthe outer sideof said casing; 1 `'1. Asi-esilient wheel cornprisingav discfor attaching 'to the hub structure of awheel. in the .usual way, a` tire rim on tthe disc, a rigid .drumlike treadcasing for theiwheelhaving a tread ring and sidemembers,.the'innerlside memberl having :an enlarged central opening .to permit the drum .to beslippecl over the hubstructure, a dirtand moisture-proof engagement between the rim and Vtheinside surface of. said inner member, and pneumatic tire meansl within the dirtand moistureproof; channel or trough-like space between the tread ring and side members andthe .rim automatically to centralize the vrim in .the ring when the wheel'is: notloaded and permitting 'same-f to become eccentricy thereto when the wheel relation on said tire andhaving a difierent angui lar `velocity and rollingr contact'therewith, a second .pneumatic tire mounted on' the .outside of said ring, and a secondring in floating relation on said second tire and having a diierent angular Velocity and rolling contact therewith. l

10. Aresilient wheel comprising a hub structure,..a rim on said structure, a pneumatic `tire mounted onsaid rim', a second rim mounted in oating relation .onsaid tire, a second pneumatic `tiremounted onsaidsecondrim, and a tread ring for'the wheel in floating relation on saidsecond tire' and having side membersv extending inwardly and overlapping said tiresv and said rims, tires'andring being coplanar and arrangedto be .automatically .rendered Yconcentric by the pressure in the tires whenftliewheel is unloaded, .and automatically to be made eccentric and to operate at different angular velocities by and proportional to the load imposed on the wheel.

11. In a resilient wheel, a hub structure, a tirecarrying rim secured thereto, a circular rigid tread casing or assembly trough-like in crosssection around the rim, coplanar pneumatic tires Within said tread casing, the inner tire being carried by the rim, and a floating rim between the coplanar tires, the inner tire operating on the inside surface of the floating rim and the outer tire being secured to the outside surface of having a dierent angular velocity androlling contact therewith', and side membersclosing' the space between said rim and tread member;

- 13..A'resilient Wheel comprising aY hubfstr-ucture, a rim'on said structure, a plurality of pneu- 'matic tires in side-by-siderrelation on said rim,

a second rim of larger diameter surrounding said 'tiresVv and having a, differentangular velocity andV Y rolling contact therewith; asecond set of tires mounted Von .said second rim, and a wheel tread 'ring oflarger diameter surrounding said second vture, a 'rim onfsaidstructurei a pneumatic Vtire mounted Von'said'rim,V a ring *surrounding the CTA tires and havingY a different angular .velocityand rolling contact therewith, and enclosing side- ;membersbetween said tread ring. and said first :'14, A resilient Wheel comprising,'in combination, `a hub structure, a rim secured'thereto, a 4tread ring surrounding the rim and having side members extending inwardly past the edges Vof the rim, pneumatictire means 4between the rim vand ring and'rcommunicatingfmotion :therebetween, the tire means engaging and causing ther Y rim and tread to be concentric when thefwheel is unloaded andv permitting them'rto become veccentric when loaded,.said rim and tread being constructed and'. connected to operate at different Aangular velocities when loadedV and rolling, and

meansy to maintain the plane of the vtread ring perpendicular to the axis of the wheel. Y

n 15, In a resilientv wheel, a hub structure; a rim Y structure secured thereto,Y a plurality of lpneu-AV matic tires mounted side by side on the rim4 struc.-

tfture, a tread Vring surroundin-g saidV tires, the

tires having different angular velocities from that Y of the ring and rolling contact on. the inside of the ring; and'means preventing the tread-ring from departing substantially fromiits normal position in which Vthat part of the outer contact surface Vof the ring which is in Vcontact'with the'road tire, 1a secondpneumatic ltire on said ringand concentricatdthe 4rst'fnamed tire, and ar tread ring for the vwheel surrounding thesecondftire, said tires engaging the surrounding rings-cir cumferentiallyA when "the wheel Vis not Vloaded but dropping'lbelow the same at the vtop when the wheel is loaded, the engagingtires and ringsgrotating at Vdiierent angular velocities and with Y rolling Contact therebetween fwhen .thel wheel is loaded and rolling., Y

18. A resilient Wheellcomprising ahub struc- .-ture, a rim onsaid structure, aV plurality. of pneumatic tires on said rim inpside-byfside relation,

and a rigid ringv surrounding said tires, said tiresV engaging the ringcircumferentially all around when the wheel is not 'loaded but droppinglbelow Ithe same at the topY when the Wheelis'loaded,

theA tiresY and Vring Vthen rotatingl at different angular velocities and with rolling contact therebetween when the wheel is rolling. t t v 19.V A resilient Wheel construction vcomprising a Yhub structure, a rim'on said structure,1a plurality of pneumatic tires in side-by-side relation on said, rim, a Vrigid. ringV surrounding saidftires; al second set `of tiresmounted on -saidring` and awheel tread ring surrounding said second set-of tires,

' the tires engaging the inside Vof the rings circum'*u ferentially when 4the wheel is not; loaded but dropping free from the same at the top 4when the Vwheel is loaded, the engaging tires and rings rotating at different angularvelocities andv withl "rolling contact therebetween when the wheely is loaded and rolling. Y A

'20. A resilient wheel comprising a tread ring,V a tire rim therein connected with the hub structure, a pneumatic tire on'thefrim and circumferentially anchored thereto at all points 'in its circumference,` the pneumatic tire engaging the l inside of theV ring and automatically centralizing Y the ring and rim when the .wheel is unloaded, said tire being lconstructed andrelatedto the parts to enable the tireand rimV to be decentralized When loaded and to rotate at different angular velocitiesand the pneumatic tire to roll` Von the inside of the ring.l ,v t f f Y ATLEE H.V TRACY. 

